So who cares about getting your first big league hit if you can make a game-saving play in your major league debut on the first ball hit to you?

That's the way it went for Oakland's Shane Peterson on Tuesday night. He went 0 for 4 at the plate with two strikeouts but made a spectacular diving stop at first base in the third inning that changed the complexion of an eventual 4-3 A's win over Houston before 11,038 at the Coliseum.

Josh Donaldson drove in the winning run with a two-out triple in the eighth inning, snapping a 3-3 tie. But without Peterson, who was called up to replace Brandon Moss after Moss' wife gave birth to a boy earlier in the day, Donaldson wouldn't have had a chance to be the hitting hero.

"You never know how the game will end up if they score those runs there," said Donaldson. "But he definitely made what you would call a game-saving play."

A's starter A.J. Griffin, a major beneficiary of Peterson's gem, fully supported that notion.

"That's the play of the game for me right there," said Griffin, who went on to pitch through the sixth and retired the last 11 hitters he faced. "Not to take anything away from Donaldson's triple, but that play was huge. It kept us in the game, and it allowed me to go out there and continue pitching. It was a momentum changer."

The Astros already had a 2-0 lead in the third inning and had the bases loaded with two out when Rick Ankiel came to the plate. On the first pitch he saw, Ankiel smashed a liner past the first base bag that appeared headed for the right-field corner.

Peterson made a sprawling dive to snare the shot and end the inning, saving at least two runs and possibly three.

"He hit it pretty hard and I didn't have time to think about it, which probably made it better for me at that time," said Peterson, who said he was nervous in the field when the game started.

Griffin was the first guy to greet Peterson in the dugout after his defensive gem.

"He put his arm around me and gave me a little punch in the stomach," Peterson said. "Then everybody just gave me high-fives, which made me feel pretty happy."